Retail managed investment funds were up 20 per cent in the September year to a total of $39.2 billion.

An analysis of funds by actuaries and researchers, Plan for Life, shows funds jumped by 7.6 per cent in the September quarter alone on the back of strong investment markets. Markets had been boosted by government stimulus and easy money programs around the world.

Boutique investment firm Milford Asset Management was the standout, with its funds under management up more than 140 per cent in the past year to $1.57b, from $656 million a year before. That took its share of total retail funds under management from 2 per cent to 4 per cent in the past year.

Milford's cash inflows from investors were up 167 per cent in the year.

Milford is led by executive director Brian Gaynor.

Milford's balanced fund showed returns of 16.1 per cent in the year to November, before tax but after fees. Returns from its active growth fund were 21 per cent. The NZX by comparison was up 18.3 per cent in the November year.

BT/Westpac funds under management were up more than 33 per cent in the year to $5.5b. Its market share also rose, to 14 per cent. BT/Westpac investor inflows were up 46 per cent.

The biggest retail funds manager remains AMP NZ with $6.6b under management, up almost 9 per cent in the year and equal to 17 per cent of the market.

Gross inflows were up almost 25 per cent in the September quarter to $3.3b, due to the usual KiwiSaver inflows.

For the total market, annual inflows into retail managed funds topped $10b, well up on the $8b in the previous September year.